Double end brush



July 28, 1964 Q E, NELSON 3,142,080

DOUBLE END BRUSH Filed Feb. 6, 1962 r .f INVENTOR.

t 42 BRooKs E. NELSON BY FIG IO L [10mm] ATTORNEYS United States Patent O 3,142,080 DOUBLE END BRUSH Brooks E. Nelson, Chagrin Falls, Ohio, assigner to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed Feb. 6, 1962, Ser. No. 171,398 12 Claims. (Cl. 15-106) This invention relates generally, as indicated, to a double end brush and more particularly to an end brush c011- struction which can quickly and easily be mounted on an arbor or pilot.

In the metal working art, when drilling holes, for example, the drill often leaves burrs or rough edges about the hole and a further finishing operation is required to spot face or deburr the drill hole. Also, in the finishing of intricate castings or the like having holes therein, it is sometimes a problem accurately to position an end brush to finish the surface adjacent the hole and end brushes employing pilots have generally been employed with the pilot projecting axially through the end brush to serve as a centering and locating means therefor. However, the life of such end brushes is relatively short and to obtain any satisfactory service from the brush, the pilot generally has to be made as a permanent part of the brush which, of course, requires an entirely different tool to spot face the hole after the drilling operation has been accomplished. Moreover, the high torque forces on the end brush generally tend to twist the brush with respect to the pilot extending axially therethrough precluding a satisfactory brushing operation.

It is accordingly a principal object of the present invention to provide a simplified double ended brush which may quickly and conveniently be inserted on a central arbor or pilot.

A further important object is the provision of an end brush construction which may quickly and easily be attached to a drill or the like for spot facing or deburring a drill hole.

Another object is the provision of a double ended brush which may be partially or completely embedded in an elastomeric material, such material enhancing the life of such brush.

A further object is the provision of an end brush having a specially shaped central aperture to permit the brush quickly and easily to be inserted on a twist drill or the like.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. l is a side elevation of a double ended brush in accordance with the present invention;

FIG. 2 is an end elevation of the brush of FIG. l;

FIG. 3 is a transverse section taken substantially on the line 3 3 of FIG. 2;

FIG. 4 is a side elevation of the brush of FIG. 1 mounted on a twist drill or the like;

FIG. 5 is a detail view showing an end elevation of the internal bristle retaining member of the brush of FIG. 1;

FIG. 6 is a side elevation of such internal member as seen from the right in FIG. 5;

FIG. 7 is a bottom plan view of' such internal member as, for example, seen from the bottom of FIG. 5;

FIG. 8 is an end elevation of another form of end brush in accordance with the present invention;

FIG. 9 is a transverse section of such brush taken substantially on the line 9-9 of FIG. 8; and

FIG. 10 is a transverse section of another form of end brush in accordance with the present invention.

Referring now to the annexed drawings and first to the brush embodiment illustrated in FIGS. 1 through 7 and more particularly to FIGS. 1 through 3, it will be seen that the brush comprises an annulus of bristle fill material 1 extending axially in each direction beyond an outer right circular cylindrical retaining member 2 and an inner corresponding annular retaining member 3. The individual filaments of the bristle fill material 1 preferably extend parallel to each other and are packed as tightly as possible between the inner and outer retaining members as shown at 4. In the present embodiment, the filaments which comprise the brush fill material 1 extend axially beyond the inner and outer retaining members 3 and 2 a distance slightly greater than the axial length of such retaining members to form annular brushing faces 5 and 6 at each end of the brush which are equally spaced from such retaining members.

For metal working or finishing operations, it is, of course, preferred to employ hard Wire bristles and either hard straight wire bristles or wire bristles of rather shallow crimp are preferred. It will, of course, be understood that any brush fill material may be employed with the present invention such as plastic coated wire bristles, horsehair, plastic coated glass fiber filaments, such as disclosed in Peterson Patent No. 2,682,734, for example, tampico or a mixture of wire and tampico or even a mixture of hard and soft wire bristles. One excellent type of brush bristle fill material that may be employed with the present invention is a fill material of a mixing of .008 diameter straight wire fill of approximately 700 Knoop hardness and a top grade tampico. Hard wire brush bristles employed with the present invention and especially steel wire will generally have a Knoop hardness of at least 600. The Knoop hardness test is a U.S. Bureau of Standards test which is particularly suited to measure the hardness of fine filaments. In some cases, the filaments` may have a hardness of at least 800. Stainless steel wire brush bristles may be employed coated With a thin outer plastic coating having beads therein as shown, for example, in the copending application of Vernon K. Charvat, entitled Brush and Brush Material, Serial No. 86,378, filed February l, 1961.

In order to limit the flexure of the bristle material and especially 'the radial fiaring of the bristles which generally result from high work pressures and high speed rotation, it is preferred to embed the entire elongated annular body of bristle fill material 1 in an elastomeric material. This material may, in some instances, be foamed and, such materials 'that are suitable may be Neoprene, polyurethane, polyvinyl chloride, or certain of 'the epoxy resins. Cellular polyurethane is, however, preferred as a foamed elastomeric material. Such polyurethane resin may, for example, be Nopco Chemical Companys resin F-202. This base resin may be mixed with a silicone, such as Dow-Corning 200 at the rate of 1.89 grams per pound of resin which is approximately .4%. A deodorant for the polyurethane manufactured by Rhodia Inc. called Alamask DW (RLT-483) may be added at the rate of three drops per pound of base resin and a colorant, Ferro Corporations well-known epoxy paste organic dye at the rate of 2.83 grams per pound of base resin, may be also added making a total of approximately .6% addition. Reference may be had to Stingley Patent No. 2,950,495 for a disclosure of a cellular Neoprene or polychloroprene which may be employed as a foamed elastomeric material for use With the present invention. A

primer may be placed on the bristle material prior to the intrusion of the elastomeric material to hold adhesively the elastomer to the bristle iill material. In this manner, the elastomer may separate between the individual bristles, but each bristle will still be provided with a protective coating which will preclude nicks or Scratches which result in stress concentrations.

Additionally, material such as polyurethane and silicone rubbers may be employed even though not cellular, when properly applied to the brush material. Polyurethane rubber intruded or blown into the brush material causes the formation of heavy membrane-like muscles between the brush wires and liller materials may be added to the polyurethane rubber so that it will have a tear strength less than its bonding strength to the wire. However, in end brush constructions, it is desirable that the brush retain its cylindrical form and accordingly the tough polyurethane rubber will preferably have a very high tear strength which will assist in the maintenance of the cylindrical shape of the brush. It has been found that brushes thus embedded with such elastomeric material will do many times more the amount of work which could be done by a conventional end brush.

As noted in FIG. 3, the outer cylindrical retainer 2 is considerably thicker than the inner retainer 3 adding to the annular gripping or retaining strength thereof. The inner member is of slightly thinner construction and is provided with diametrically opposed inwardly extending indentations 8 and 9 which when viewed from the end provides an hourglass-like opening 10 through the inner diameter of the brush. The inner member 3 is also provided with two outwardly extending diametrically opposed indentations 11 and 12 which form, in effect, tins extending longitudinally of the member. These tins, of course, protrude into the compact annular central portion of the brush bristle ll material 1 and preclude relative rotation of the various components of the brush. These ns or ribs are spaced approximately 90 from the inwardly extending circular indentations 8 and 9. The hourglass profile of the internal opening thus provided by the indentations S and 9 provides an internal opening through the brush which is relatively clear of any obstruction so that a fluted drill or reamer, or any other grooved tool or pilot that would be appropriate, can be inserted into the brush and the indentations 8 and 9 will fit within the ilutes, for example, of a twist drill. With special reference to FIG. 4, there is shown a twist drill 14 which has the conventional spiral flutes 15 and 16 on diametrically opposite sides thereof. The drill may be placed within the brush simply by placing the tip 17 Within one end opening and rotating the drill shank as the brush is moved axially of the drill. The indentations 8 and 9 will be accommodated within the iiutes and 16 respectively. The indentations 8 and 9 also serve as a locking means to preclude relative rotation of the drill shank and brush when in use. A locking collar 18 is secured to the shank of the drill by a set screw 19 or the like and serves as a stop collar abutting the end face 5 of the brush which will not be employed. The stop collar precludes distortion of the bristle body which might otherwise occur.

When the brush is thus secured, the end portion 2u of the shank of the drill may then be secured in a collet chuck or the like and the tip of the drill protruding through the brush will serve as a pilot to guide the workface 6 to the proper work surface. It will, of course, be understood that the drill need not be removed from the collet chuck to have the brush inserted thereon. The collar will rst be slid over the tip 17, secured in place by the set screw 19, and the brush may then be driven or rotated onto the drill until the workface 6 is in engagement with the collar. The same drill may then be used as the pilot for the brush which was employed to drill the hole. It is noted that the hourglass prolile of the internal opening permits not only a twist drill to be readily inserted, but a plain or grooved cylindrical member may be forced 'through the opening and the inwardly directed indentations 8 and 9 will be employed to grip the pilot.

Referring now to the embodiment of FIGS. 8 and 9, it will be seen that a similar double ended brush is provided having annular axially extending brush till body 25 which is gripped between anI outer cylindrical retaining member 26 and an inner retaining member 27. Such inner member is provided with outwardly projecting teeth 28 and 29 which may be punched from the end edges of such inner member 27. These teeth project into the densely packed inner portion 39 of the bristle till material between the annular retaining members 26 and 27. The axially extending fill material provides oppositely directed annular end faces 31 and 32 either of which may be employed in a brushing operation. The brush is preferably embedded in an elastomeric material, such as the poiyurethane rubber, and when embedded, a core member may be inserted in the annular opening provided by the inner member 27, such core member having spiral lands and grooves corresponding roughly to the lands and grooves of a twist drill. In this manner, the elastomer will form interior diametrically opposed lands 33 and 34 and grooves 35 and 36 therebetween. After the elastomer is embedded within the brush and properly cured, the core may be pulled outwardly by twisting the same to produce the hourglass spiral opening 37 through the center of the brush. The center hole thus formed then readily accommodates drills of varying sizes and it becomes possible in a drilling operation; to place the collar 18 on the shank of the drill; to place a hole in the workpiece; to pull the drill out of the hole; readily insert the brush on the shank of the drill with the end face 31, for example, contacting the collar; and then reinsert the drill in the hole to spot face or deburr the workpiece area adjacent the hole. In an automatic drilling operation, this can be accomplished without laterally indexing the drill. Of course, when one of the end faces 31 or 32 becomes excessively worn, the other end face may be employed.

Referring now to FIG. l0, there is illustrated a more or less permanent end brush which may be mounted on a drill shank dit by means of set screws 41 and 42. Such end brush is mounted in a cup 43 having an opening 44 in the bottom thereof accommodating such drill shank. Axially extending bristle fill material 45 may be positioned within the cup and elastomer such as the aforementioned polyurethane rubber may be embedded in the brush as shown at 46, such elastomer extending beyond the edge 47 of the cup to approximately slightly more than half the extended length of the bristles as shown at 48. This extended portion of the elastomer from the cup edge along the outside of the annular birstle lill material serves as a bridle to keep the axially projecting till material from aring outwardly. In this embodiment, the drill is preferably permanently secured within the brush and the tip serves as a pilot for the spot facing of work adjacent holes or the like. The polyurethane rubber may be caused to feather out as shown at 49 toward the working face 50 of the brush and this, of course, reduces the flexibility of such bristles and precludes excessive bristle fracture.

It can now be seen that there is provided a simpliiied end brush construction which may quickly and easily be mounted on a pilot. Moreover, the simplified inner ring structure of the FIG. l embodiment permits the double end brush readily to be twisted onto a twist drill or the like with the indentations 8 and 9 serving as keys fitting in the flutes of the twist drills as keyways preventing relative rotation of the brush and drill. In the FIG. 8 embodiment, the molded elastomer lands and grooves serve a similar purpose. The axially extending annular brush iill is firmly clamped between the annular inner and outer clamping rings as the inner ring is provided with lill material indentations to preclude any relative movement in a circumferential direction of the ring and the fill material. It has been found that with the brush of the present construction, greatly increased brush life is obtained and by embedding the material in an elastomer, foamed or non-foamed, the axial parallel projections of the bristles can be maintained which, of course, increases the effective life of such brush.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. An end type rotary brushing tool comprising an annular body of parallel bristle filaments, said bristle filaments being densely packed in a central base portion between inner and outer annular retaining members, said inner retaining member including radially outwardly projecting portions projecting within such densely packed bristle filaments, and means projecting inwardly from said inner retaining member operative to engage and hold a pilot inserted through said tool.

2. A double ended brush comprising an annular row of densely packed parallel bristle filaments, an outer cylindrical retaining member centrally surrounding said filaments, an inner retaining member compressing such filaments against said outer retaining member, said inner member including diametrically opposed inwardly extending indentations adapted to engage a pilot extending through said tool.

3. An end brush as set forth in claim 1 including an elastomeric material embedded within said bristle material.

4. The end brush of claim l wherein the inwardly projecting means comprises elastomeric ridges molded to said inner retaining member.

5. The end brush of claim l in which an arbor with engagement means thereon is positioned within said brush in locking engagement with said inwardly projecting means.

6. The end brush of claim 5 in which said engagement means comprises spiral grooves in said arbor.

7. A double end brush comprising an annular row of parallel bristle filaments, an outer cylindrical retaining member surrounding said annular filaments, an inner retaining member cooperating with said outer retaining member to compress the midportions of said filaments against said outer retaining member, said inner retaining member including means projecting radially into said filaments, and means projecting radially inwardly of said inner retaining member adapted to secure such brush to a pilot.

8. A double end brush as set forth in claim 7 wherein said means projecting radially into the filaments comprises axially extending ribs on said inner retaining member.

9. A double end brush as set forth in claim 7 wherein said means projecting radially into said brush filaments comprises teeth punched from said inner retaining member.

l0. A double end brush comprising a central retaining member, brush filaments projecting axially of said central retaining member, and means projecting inwardly from said retaining member with an hourglass profile opening extending axially through said inwardly projecting means and said brush.

11. The brush as set forth in claim 10 wherein said hourglass profile opening spirals through said brush.

12. The brush of claim 11 in which an arbor with spiral grooves therein is secured in locking engagement in said hourglass opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,460,883 Bougher July 3, 1923 1,507,971 Lomp Sept. 9, 1924 1,540,858 Pitcher June 9, 1925 1,706,862 Rickersberg Mar. 26, 1929 1,750,451 Wrightson et al. Mar. ll, 1930 2,191,721 Milarch Feb. 27, 1940 2,421,647 Peterson June 3, 1947 2,486,363 Purvis Oct. 25, 1949 2,667,795 Bowen Feb. 2, 1954 2,932,050 Weiler Apr. 1.2, 19.60 

10. A DOUBLE END BRUSH COMPRISING A CENTRAL RETAINING MEMBER, BRUSH FILAMENTS PROJECTING AXIALLY OF SAID CENTRAL RETAINING MEMBER, AND MEANS PROJECTING INWARDLY FROM SAID RETAINING MEMBER WITH AN HOURGLASS PROFILE OPENING EXTENDING AXIALLY THROUGH SAID INWARDLY PROJECTING MEANS AND SAID BRUSH. 